Dr.
Swann Spoilers From "Sacred"How
is the fate of Dr. Swann (the character played by Christopher
Reeve) revealed to Clark?

From
this week's TV Guide:

"The
day after Dr. Swann dies, Clark receives a note from the professor
leading him to a message from Jor-El that insturcts him to find
two sacred stones. Meanwhile, Jason and Lex are on a related
mission."